A journalist from London in her early 30s and the novel's protagonist. Her humor, quick wit, and trustworthiness appeal to everyone that she corresponds with, particularly the Guernsey islanders. While living in London during World War II, Juliet had written a humorous column in The London Times that was eventually published into a largely successful book. Although Juliet loves her career, she tires of only being known for her humor and yearns to write something serious. In the beginning of the novel, she is rather discontent. However, inspiration soon arrives in the form of letters from the people of Guernsey. Her personal journey from boredom to joy and self-fulfillment is ongoing and aided by her connection with the Guernsey islanders.

Juliet's character is largely molded by her childhood: she was orphaned by the age of 12, raised by an uncle who paid little attention to her, and spent most of her childhood in a boarding school. However, she remained psychologically strong through it all and developed into a kind, independent, and self-assured young woman. She is free-spirited, spontaneous, and endlessly devoted to her loved ones. In her adulthood, Juliet refuses to be any man's trophy wife, no matter how handsome and rich he may be. Her personal independence is of utmost importance throughout the novel. However, she finally finds love and the never-experienced feeling of family while on Guernsey. Although her morals remain steadfast, Juliet experiences numerous changes in terms of what direction her future will ultimately take. The solutions to Juliet's decisions are not always obvious to her — although she is exceedingly smart and capable, Juliet sometimes needs someone to point out what stands right in front of her.